Apparatus for safety burning crude oil on a marine tanker



1968 R. c. MAORRELL 3,36

APPARATUS FOR SAFETY BURNING CRUDE OIL ON A MARINE TANKER Filed April 14, 1966 3 Sheets-:Sheet 1 H F|G-8 A 5 INVENTOR ROBERT C-MORRELL man 57 ATTORNEY R. C. MORRELL APPARATUS-FOR SAFETY BURNING CRUDE'OIL ON A MARINE TANKER Filed April 14, 1966 Jan. 9, 1968 3 Sheets-Sheet 2 v7 m5 mm m $525 5235 w\ .2953 355% 28m 562% 2 2.28 855 Qm 8m INVENTOR R OBER I TC. BELL I J K.

ATTORNEY Jan. 9, 1968 R. c. MORRELL 3,362,370

APPARATUS FOR, SAFETY BURNING CRUDE OIL ON A MARINE TANKER Filed April 14, 1966 3 Sheets-Sheet :5

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3 BOILER FRONT v I U INVENTOR v ROBERTC- MORRELL 4 34 I 3 v am F 6.6 AT O E United States Patent 3,362,370 APPARATUS FOR SAFETY BURNING CRUDE OIL ON A MARINE TANKER Robert C. Morrell, Centerport, N.Y., assignor to Cities Service Tankers Corporation, New York, N.Y., a corporation of Delaware Filed Apr. 14, 1966, Ser. No. 542,641 3 Claims. (Cl. 114-74) ABSTRACT OF THE DISCLOSURE Apparatus is provided for utilizing crude oil as fuel for tankers and includes a fuel line leading from a storage tank to the burners at the boiler, valving at the boiler face to allow burning of either crude oil or bunker fuel, pumps, strainer and a main shut-off valve in the pump room and a drip collector in the engine room with a line for removing oil drippings. Recirculating valves and conduits are also provided for allowing circulation of crude oil prior to firing of the burners. A hood is positioned in the engine room above the face of the boiler where the crude oil flow control valves are located and all crude oil and oil drippings lines are protected with externally vented, vapor tight ducting along the sections thereof located in the engine room area and not protected by the hood. The drip collector is protected with a flame screen and the hood is vented to the atmosphere by an exhaust fan having a safety interconnect to shut off flow of crude oil into the engine room area in the event of exhaust fan failure.

This invention provides improvements in marine oil tankers, and more particularly provides a novel apparatus arrangement for safely utilizing crude oil as a fuel for the power plant of a tanker.

The power plant of an oil tanker may be conveniently divided into two components, the steam-generating machinery and the steam-using machinery, or into simply steam generators and engines. Heretofore, it has been customary to use bunker oil, heavy crude oil or other relatively high flash point oils as the fuel for generating steam. While under certain circumstances it would be desirable to employ relatively low flash point crude oils, e.g. below 150 F., this practice is extremely hazardous because of the danger of explosion from the light ends present in such crudes. In fact, the use of crude oil having a flash point below 120 F. as a fuel for conventional tanker power plant systems has not heretofore been permitted by the American Bureau of Shipping.

Accordingly, it is one object of the present invention to provide apparatus for safely using relatively low flash point crude oil as a fuel for the power plant of a marine tanker.

It is another object of the invention to provide apparatus for safely burning crude oil having a flash point below about 150 F., e.g. below 120 F., as a fuel for the power plant of a marine tanker.

It is another object of the invention to provide apparatus which enables the safe burning of a relatively low flash point crude oil, but is also adaptable to the burning of more conventional high flash point fuels, such as bunker oil, when economic considerations dictate burning of such conventional fuels.

Various other objects and advantages of the invention will become apparent to those skilled in the art from the following detailed description thereof, taken in conjunction with the accompanying drawing which illustrates a preferred embodiment of the invention and in which:

, FIGURE 1 is a profile view of the after body of a marine tanker including a diagrammatic representation of a portion of the apparatus arrangement of the invention;

FIGURE 2 is a schematic diagram of the apparatus arrangement of the invention;

FIGURE 3 is a cross-sectional view taken along the line 3--3 of FIGURE 2 of the protective duct and various oil-carrying conduits contained therein;

FIGURE 4 is a vertical cross-sectional view of the port boiler diagrammatically illustrating the arrangement of piping on the boiler front;

FIGURE 5 is a front elevation view of the port boiler;

FIGURE 6 is a top elevation view illustrating the relationship of the hood arrangement to the boiler;

FIGURE 7 is a diagrammatic representation of the ventilating arrangement of the boilers; and

FIGURE 8 is a wiring diagram of a safety interlock circuit preferably employed in conjunction with the apparatus of the invention.

More particularly, FIGURE 1 illustrates the relative locations of oil compartments, pump room and power plant area, i.e. boiler room and engine room, on a typical 13-tank vessel. The aft oil tank, designated by reference numeral 1 and having starboard and port compartments (starboard compartment being shown in the drawing) is separated from the pump room 2 by an oil-tight bulkhead 3 extending from the upper deck 4 to the keel of the vessel. Likewise, the pump room 2 is separated from the engine room 5 by bulkhead 6, while the engine room is separated from the boiler room 7 by bulkhead 8 extending from the upper deck 4 to the flat deck 9, as well as by bulkhead 10 extending from flat deck 9 to the tank top of the vessel. Located above the pump room area 2 is a crossbunker tank 11 which is separated from the crude compartment 1 by a cofferdam 12. The cross-bunker tank 11 is normally used for carrying bunker oil fuel.

Referring now to FIG. 2 in conjunction with FIG. 1, when it is desired to burn low flash point crude oil, i.e. crude having a flash point below 150 F., for instance below F., in accordance with the invention as a fuel for generating steam, the crude may be withdrawn from a cargo tank, for instance, the starboard compartment of the after-most tank 1, through supply conduit 13 provided with a valve 14 and then passed through strainer 15 positioned on the suction side of a pump 16 for the purpose of removing grit, sand and the like which may be present in the crude. If desired, a second strainer 17 may be provided on the discharge side of the pump 16. The crude oil supply conduit 13 is provided with a main crude oil shut-off valve 18, which is preferably air-operated as will hereinafter be more fully described.

Crude oil supply conduit 13 extends through the engine room 5 and supplies the burners of the port and starboard boilers 19 and 20, respectively. Since the arrangements of piping and other equipment serving the port and starboard boilers are identical, the invention will be further described with reference to the port boiler 19 for the purpose of simplicity. Thus, it will be understood that the components of the equipment of the starboard boiler which function identically to equipment components hereinafter described in reference to the port boiler are designated on the drawing by reference numerals which are the same as those applied to the equipment components of the port boiler, but are prefixed by the numeral 1.

Referring now to the port boiler 19, main crude oil supply conduit 13 leads into port boiler supply conduit 21 which is provided with a valve 22 for regulating the flow of oil to the burner means of the boiler. The port boiler may comprise three burners, which are represented by the reference numerals 23a, 23b and 230. Crude oil is supplied to each of the burners by means of separate feed lines 24a, 24b and 240 which lead from the port boiler supply conduit 21. Each of the 'feed lines is preferably provided with a 3-way cock valve a, b and c, and a flow control valve 26a, [1 and c.

The burners may be of any conventional design. For example, the crude oil may be charged to the burners as a steam-atomized spray and mixed therein with air introduced by forced draft. The burner will preferably be provided with various safety features, namely, remotely-operated spark igniter and air damper, and an ultra-violet scanner to determine the existence of a flame. These safety features are known in the art, and accordingly form no part of the present invention.

As best shown in FIGURE 4, steam for atomizing the crude oil spray to the burners may be passed from a steam source 27 through conduit 28 having control valves 29a, b and c for controlling the amount of steam charged to each burner 23a, 12 and c, and then delivered to each burner through individual steam feed lines 39a, b and c.

In preparing for the burning of crude oil fuel, it is necessary to insure that the oil will be supplied to the burners under sufiicient pressure upon ignition of the burners. For this purpose, port boiler supply conduit 21 is provided with a recirculating valve 31 which is open prior to ignition of the first burner to be lit-off. With valve 31 opened, crude oil is recirculated through recirculation conduit 32 back to main supply conduit 13 at a location upstream from the pump 16. However, after ignition of the first burner, valve 31 is normally closed.

The various conduits and valves required in the boiler room for supplying crude oil to the burners may be mounted on the boiler front and covered by a hood arrangement 33. As shown in FIGURES 4, 5 and 6, the hood 33 extends outwardly from the upper front section of the boiler casing, and then downwardly over the valves and piping mounted thereon. The side panels of the hood extend from the top to the bottom of the boiler casing, while the front section thereof extends downwardly from the top only a sufficient distance to cover the valves, thereby leaving an open area for the entry of boiler room air. The front section of the hood may be provided with hinged doors 34 to enable convenient access to the valves and piping disposed therebehind.

Venting of the boiler space under the hood is accomplished by means of a vent duct 35. Air and any crude oil vapor present pass into vent duct 35 through an adjustable screened opening 36 in the side plate of hood 33, and are vented to the atmosphere. As shown in FIG- URE 7, the vent ducts 35 and 135 leading from the fronts of the port and starboard boilers, respectively, may be led into a common duct 37 having an exhaust fan 38 and extending to a deck of the tanker. The end of the vent duct 37 opening on the tanker deck may be provided with a flame screen (not shown), which may suitably be 30 mesh Monel metal.

Positioned below the hood 33 is a drip pan 39 which serves to collect any crude oil drippings from the valves and piping mounted on the boiler front. The drip pan 39 is covered with a flame screen 40 of "a suitable mesh size which would permit oil to enter the drip pan, but would contain any fire developing therein.

An essential feature of the present invention is that all crude oil-carrying pipes and valves located in the power plant area of the tanker, ie the boiler room and the engine room, are arranged in a manner such that free oil vapors and drippings are not permitted to come in contact with any source of ignition in the power plant. Thus, as just noted, the piping and various supply and other valves mounted adjacent the boiler front are covered by a hood 33 which is vented to the atmosphere. Furthermore, a drip pan 39 covered by a flame screen is positioned below the valves and piping mounted on the boiler front to collect oil drippings. All oil-carrying piping extending through the power plant area and not protected by the hood is, in accordance with the invention, enclosed in a vapor-tight duct 41. Thus, the vapor-tight duct 41 extends from the forward engine room bulkhead 6 to a vapor-tight connection box 42 which is mounted to the bottom of the drip pans 39 and 139 of the port and starboard boilers, respectively. Extending into the connection box 42 from the port drip pan 39 is a drain conduit 43 which is provided with a U-shaped vapor trap. Likewise, a drain conduit 143 having a U-shaped vapor trap extends into the connection box 42 and leads into drain conduit 43 from the starboard drip pan 139. As shown in FIGURES 1 and 2, drain conduit 43 runs from the connection box 42 through the vapor-tight duct 41 throughout the power plant area. When outside of the power plant, for example, in the pump room 2, drain conduit 43 is led into a drain tank 44 provided with a vent 45 leading to a deck of the tanker for venting the drain tank to the atmosphere. Drain conduit 43 and encompassing duct 41 are, as shown in FIGURE 1, sloped downwardly from the connection box 42 to provide proper drainage to the drain tank 44.

Main supply conduit 13 also run through vapor-tight duct 41 into connection box 42 and then through flange 46, which is disposed in flame screen 40, whereupon it leads to the piping arrangement mounted on the boiler front under the hood 33. Likewise, recirculation conduit 32 leads from under the hooded area in front of the boiler through flange 47, which is disposed in port boiler flame screen 40, into connection box 42 and then runs through pipe duct 41 until it enters the pump room area 2 of the tanker.

The supply, recirculation and drain conduits may be positioned within the vapor-tight duct 41 in any convenient manner. For instance, as shown in FIG. 3, the recirculation conduit 32 and drain conduit 43 may be secured to stud 48 by bolted brackets 49 and 50, respectively, while supply conduit 13 may be secured to stud 51 by bolted bracket 52.

The vapor-tight duct 41 may be vented to the atmosphere by means of a vent duct 53 extending upwardly through the engine room area to deck of the tanker.

In accordance with a preferred embodiment of the invention, an interlock control is provided between the exhaust fan 38 in the hood vent duct 37 and the main shutoff valve 18 is crude oil supply conduit 13, whereby flow of crude oil to the power plant area of the tanker is'permitted only when exhaust fan 38 is operative. A suitable electrical circuit arrangement for this purpose is shown in FIGURE 8. Thus, the interlock circuit includes a normally closed contact 54 in the motor of exhaust fan 38 and a magnetic air pilot valve 55 which are connected in series and operated off of the ships AC power source 56 by means of power lines 57 and 58. Upon failure of the exhaust fan motor, contact 54 opens, thereby energizing magnetic .air pilot valve 55 to supply air to close main crude oil valve 18. It will be noted that the circuit is also provided with a manually-operated switch 59, whereby the operator may shut main crude oil valve 18 if a dan gerous situation arise in the power plant.

As has been previously noted, the burning of low flash point crude oil in lieu of the more conventional fuels, such as, bunker oil, is particularly desirable when the crude oil may be obtained more economically than the bunker. For example, when the price of crude oil loaded on the tanker is less than the price of bunker oil at the loading port, it would be economically desirable to burn crude oil as a fuel on the voyage to the discharging port. However, on the return voyage, it may be economically more desirable to burn bunker oil instead of crude, particularly, when the price which can be obtained for crude oil at the discharging portion is greater than the price which must be paid for bunker at the discharging port. The apparatus provided by the present invention for safely burning crude may be readily adapted to the burning of bunker oil when such practice is economically more desirable. Thus, one or more of the burners may be taken off crude oil feed and put on bunker oil feed by adjustment of 3-way cock valves 25a, b and c. The bunker oil may be supplied to the burners in a conventional manner from the cross-bunker tanks 11, or other suitable source. Bunker oil supply conduit 59, which leads from the bunker oil source, is provided with valves 60a, b and c for controlling the flow of bunker to the individual burners through individual feed lines 61a, b and 0, respectively, leading into the 3-way cock valves 25a, [2 and c. Bunker oil supply conduit 59 need not be encased in a vapor-tight duct, as is required in the case of the crude oil supply conduit.

While the invention has been described above in connection with certain preferred embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as expressed in the appended claims. Thus, the invention is not limited to the particular locations of the pump room, engine room and boiler room illustrated in the drawings. For example, the pump room and/ or power plant area may be located at midship. Furthermore, it is not necessary that the various valves and conduits required in the boiler room for supplying crude oil to the burners be mounted on the boiler front. For example, the valves may be enclosed within a gas-tight hood located in the boiler room and vented to the atmosphere, and a drip pan may be positioned below the valves. With such an arrangement, however, it would be necessary to encase crude oil-carrying conduits extending from the valves to the hooded area over the boiler in a vapor-tight duct.

Therefore, I claim:

1. In an oil tanker vessel having a crude oil holding compartment, a pumping area containing pumping means for pumping said crude oil and a power plant area con taining steam generating means, including burner means, and steam driven engine means, apparatus for safely burning crude oil in said burner means to operate said steam generating means and generate steam for driving said engine means comprising:

(a) supply conduit means interconnecting said crude oil compartment, said pumping means and said burner means for supplying crude oil to said burner means, said supply conduit means having main shutoff valve means positioned between said pumping means and said power plant area;

(b) crude oil flow control valve means located in said power plant area for controlling the flow of crude oil to said burner means;

(c) protective hood means positioned in said power plant area above said crude oil flow control valve means, said hood means being provided with an exhaust fan and vented to the atmosphere;

((1) main shut-off valve control means responsive to failure of said exhaust fan to close said main shut off valve means, whereby flow of crude oil to said power plant area is permitted only when said exhaust fan is operative;

(e) crude oil drip collecting means positioned in said power plant area to collect crude oil drippings from the crude oil flow control valve means and the burner means in such area;

(f) conduit means for removing collected crude oil drippings from said drip collection means;

(g) a flame screen positioned above said drip collecting means and adapted to prevent spread of flames from the drip collecting means into the power plant area; and

(h) vapor tight duct means enclosing said supply conduit means and said conduit means for removing collected crude oil drippings at least along the sections thereof located in portions of the said vapor tight duct means being vented to the atmosphere.

2. Apparatus according to claim 1 in which the protec tive hood means extends downwardly to an elevation below the crude oil flow control valve means and is positioned so that air may flow into the area covered by the hood means from below the level of the crude oil flow control valve means under the influence of the exhaust fan.

3. Apparatus according to claim 1 including recirculation conduit means for recirculating crude oil from the power plant area back to the pumping area and recirculation control valve means located in the pilot plant area under the protective hood means for controlling flow of crude oil from the supply conduit means either to the burner means or back through said recirculation conduit means to the pumping area, said recirculation conduit means being enclosed within the vapor tight duct means at least along the section thereof located in portions of the power plant area not covered by said hood means, and said vapor tight duct means being vented to the atmosphere.

References Cited UNITED STATES PATENTS 744,373 11/1903 Lovekin et a1. 15836.3 2,516,150 7/1950 Samiran 244 2,780,206 2/1957 Rocque et a1. 15836 2,838,042 6/1958 Chen.

3,149,642 9/1964 Marx 137-5S7 X 3,272,168 9/1966 Donohue et' al 114-74 FERGUS S. MIDDLETON, Primary Examiner. MILTON BUCHLER, Examiner.

T. M, BLIX, Assistant Examiner. 

